A. Field of the Invention
The invention relates to the field of seat posts and seat mounting clamps for bicycles and other human-powered vehicles. More specifically, the invention relates to the field of adjustable seat posts and seat mounting clamps for bicycles and other human-powered vehicles which allow seat position and angle adjustment.
B. Description of Related Art
Cycle riding is becoming one of the most popular sporting activities. This pleasurable activity can be enjoyed by persons of all ages, from the very young to the elderly. As the popularity of this sport has increased, the varieties of cycles and cycling accessories available have also correspondingly increased. The types of cycles which are available include unicycles, bicycles, tricycles and multi-rider cycles (hereafter collectively referred to as "bicycles"). For the cycling enthusiast, bicycles are available for riding on roads, trails, hills and mountains. Bicycles have also been adapted for indoor use as exercise cycles.
As the popularity of bicycling has increased, manufacturers and riders alike have sought to make bicycles more comfortable to ride and more light-weight. One way in which manufacturers have improved the comfort of bicycle riding is to provide bicycle seats and seat posts which facilitate "micro-adjustment" of the seat position and angle to suit a particular rider.
Bicycle seats typically include truss structures to support the saddle. An example of such truss structure is disclosed in U.S. Pat. No. 5,294,173, which is incorporated by reference herein in its entirety. The typical truss structure used today is a shaped wire of appropriate thickness and strength to support the weight of a rider's body under expected riding conditions. The truss structure is the point at which typical bicycle seats are attached to the bicycle frame, via a bicycle seat post assembly.
There are bicycle seats which include an angular adjustment mechanism on the seat frame. An example of such a bicycle seat is disclosed in U.S. Pat. No. 4,231,611, which is incorporated by reference herein in its entirety. Such a bicycle seat includes a seat clamp having a receptacle for receiving a support post. The clamp includes a horizontally -oriented clamp body which may be rotatably mounted to adjust the tilt or angular relationship between the seat and the post. The tilt of the seat post may be adjusted by loosening of a nut and bolt with a tool, adjusting the tilt of the seat and then tightening the nut and bolt combination.
Bicycle seat post clamps have been designed which grip a seat truss structure in a clamp while allowing angular adjustment, and fore and aft adjustment, of the seat. Various seat post clamps are disclosed in U.S. Pat. Nos. 4,983,063, 4,987,764, 5,020,851, 5,123,698, 5,226,624, and 5,244,301. Each of these patents is incorporated by reference herein in its entirety. These seat post clamps typically have an angular adjustment mechanism offset from the longitudinal axis of the seat post. The angular adjustment mechanism typically includes a pair of clamps, the meeting surfaces of which are flat or convex. Because the component clamps fail to fully engage each other, a seat held by such a mechanism is likely to slip while occupied by a user.
Seat post connector members have been designed which clamp both to a seat post and to a seat frame and allow angular adjustment of the bicycle seat. Such a device was disclosed in a U.S. Pat. No. 5,330,283, which is incorporated by reference herein in its entirety.
Quick-release mechanisms have also been adapted for use with bicycle seat posts to facilitate quick adjustment of the angle and position of bicycle seats. One such device is disclosed in U.S. Pat. No. 4,919,378, which is incorporated by reference herein in its entirety. This device uses a pair of seat posts which are adjustably fixed to each other. The relative adjustment of the seat posts is made by releasing the quick release mechanism, adjusting the seat position and then tightening the quick release mechanism.
U.S. Pat. Nos. 4,789,172, 4,789,176 and 5,224,726 disclose quick action saddle post clamps or assemblies which are designed to allow the height of a bicycle seat to be adjusted without the use of tools. U.S. Pat. No. 4,807,856 discloses an adjustable bicycle seat post with spring-biased mechanism for adjusting seat height. These devices do not, however, allow the seat angle or the fore-aft position to be adjusted.
A wedge-shaped seat post assembly is described in U.S. Pat. No. 5,033,790, in which a clamping member is formed of multiple wedge-shaped pieces atop a seat post. This patent is incorporated herein in its entirety. The clamping member allows angular and fore-aft adjustment of a bicycle seat. A bolt or other fastening member is used to pull the wedge-shaped pieces together, thereby clamping the seat truss shafts in place.
U.S. Pat. Nos. 5,048,891 and 5,395,155 each disclose a seat position changing apparatus in which the truss of the seat is fixedly secured to the top of a seat post. These patents are incorporated by reference in their entirety. A separate adjustment mechanism allows the seat angle and position to be adjusted. Adjustment may be controlled by a handlebar control.
U.S. Pat. No. 5,295,727 discloses a bicycle seat adjusting device allowing fore and aft adjustment, and angular adjustment, of a bicycle seat. This patent is incorporated by reference herein in its entirety. The bicycle seat post has a U-shaped support at the upper end of a seat post. A pair of horizontally oriented hexagonal bolts lock a pair of retainers in place. Adjustment is controlled by turning an adjusting lever to loosen hexagonal bolts, which allows the retainers to rotate, thereby allowing angular and fore-aft adjustment of the seat.
U.S. Pat. No. 4,783,119 discloses an adjustable saddle mount using separate angular and fore-aft adjustments. The angular adjustment mechanism includes a half spool shaped part which fits into a similarly shaped recess at the end of the seat post. A pair of bolts located outside the assembly secure the angular adjustment mechanism by gripping clamp bars located atop the assembly. The clamp bars also secure the truss structure of the seat. This patent teaches the use of a pair of fixing bolts with a wide spacing to allow the use of smaller, more light-weight fasteners.
U.S. Pat. No. 5,190,346 discloses an adjustable wraparound bicycle seat post clamping apparatus using a single fastener. The clamping mechanism includes upper and lower rail clamping means. The upper rail clamping means has an arcuate surface to facilitate adjustable attachment with the seat post clamping apparatus. The lower rail clamping apparatus also has an arcuate surface corresponding to the arcuate upper surface of the upper end of the seat post. The seat post clamping apparatus includes a hole means extending horizontally through the upper end of the seat post tube, a rod means extending through the hole means, and a wrap around member which covers the upper rail clamping means. The wrap around member is held in place by a detachable securement means engaging the rod means and the wrap around member. The securement means is located on the outside of the apparatus. A disadvantage of this apparatus is that the hole means, which extends through the end of the seat post tube, weakens the seat post tube. The securement means requires a tool to allow adjustment of the angle and fore-aft position of the seat.
U.S. Pat. Nos. 5,007,675 and 5,149,034 disclose seat adjustment devices which are controlled by a handle mounted release lever. Both of these devices also use multiple posts to position the seat, and thus, like the device of Iwasaki and Akamatsu, are heavy and require strengthened joints because the adjustment mechanism is offset from the longitudinal axis of the seat post tube.
Suspension devices have also been developed for use with bicycle seats and seat posts. Such devices are disclosed in U.S. Pat. Nos. 4,456,295, 5,044,648, 5,301,974, 5,236,169, 5,236,170 and 5,397,094, each of which is incorporated by reference herein in its entirety. Most of these devices are suitable for combination with other mechanisms which allow adjustment of the height, angle or fore-aft position of a bicycle seat.
There is a need for a light-weight seat post clamp which allows secure and precise adjustment of the angle and fore-aft position of a bicycle seat. Such a seat post clamp may be adjusted with or without the use of separate tools. Such a bicycle seat attachment mechanism may be offset from the longitudinal axis of the seat post, or substantially in line with the longitudinal axis.